content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // http://code.google.com/p/protobuf/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf.test;
  import com.google.protobuf.*;
  
  import com.google.protobuf.DescriptorProtos.DescriptorProto;
  import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
  import com.google.protobuf.DescriptorProtos.EnumValueDescriptorProto;
  import com.google.protobuf.DescriptorProtos.FieldDescriptorProto;
  import com.google.protobuf.DescriptorProtos.FileDescriptorProto;
  import com.google.protobuf.Descriptors.DescriptorValidationException;
  import com.google.protobuf.Descriptors.FileDescriptor;
  import com.google.protobuf.Descriptors.Descriptor;
  import com.google.protobuf.Descriptors.FieldDescriptor;
  import com.google.protobuf.Descriptors.EnumDescriptor;
  import com.google.protobuf.Descriptors.EnumValueDescriptor;
  import com.google.protobuf.Descriptors.ServiceDescriptor;
  import com.google.protobuf.Descriptors.MethodDescriptor;
  
  import com.google.protobuf.test.UnittestImport;
  import com.google.protobuf.test.UnittestImport.ImportEnum;
  import com.google.protobuf.test.UnittestImport.ImportMessage;
  import protobuf_unittest.UnittestProto;
  import protobuf_unittest.UnittestProto.ForeignEnum;
  import protobuf_unittest.UnittestProto.ForeignMessage;
  import protobuf_unittest.UnittestProto.TestAllTypes;
  import protobuf_unittest.UnittestProto.TestAllExtensions;
  import protobuf_unittest.UnittestProto.TestExtremeDefaultValues;
  import protobuf_unittest.UnittestProto.TestRequired;
  import protobuf_unittest.UnittestProto.TestService;
  import protobuf_unittest.UnittestCustomOptions;
  
  
  import junit.framework.TestCase;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * Unit test for {@link Descriptors}.
   *
   * @author kenton@google.com Kenton Varda
   */
  public class DescriptorsTest extends TestCase {
  
    // Regression test for bug where referencing a FieldDescriptor.Type value
    // before a FieldDescriptorProto.Type value would yield a
    // ExceptionInInitializerError.
    @SuppressWarnings("unused")
    private static final Object STATIC_INIT_TEST = FieldDescriptor.Type.BOOL;
  
    public void testFieldTypeEnumMapping() throws Exception {
      assertEquals(FieldDescriptor.Type.values().length,
          FieldDescriptorProto.Type.values().length);
      for (FieldDescriptor.Type type : FieldDescriptor.Type.values()) {
        FieldDescriptorProto.Type protoType = type.toProto();
        assertEquals("TYPE_" + type.name(), protoType.name());
        assertEquals(type, FieldDescriptor.Type.valueOf(protoType));
      }
    }
  
    public void testFileDescriptor() throws Exception {
      FileDescriptor file = UnittestProto.getDescriptor();
  
      assertEquals("google/protobuf/unittest.proto", file.getName());
      assertEquals("protobuf_unittest", file.getPackage());
  
      assertEquals("UnittestProto", file.getOptions().getJavaOuterClassname());
      assertEquals("google/protobuf/unittest.proto",
                   file.toProto().getName());
  
      assertEquals(Arrays.asList(UnittestImport.getDescriptor()),
                   file.getDependencies());
  
      Descriptor messageType = TestAllTypes.getDescriptor();
      assertEquals(messageType, file.getMessageTypes().get(0));
      assertEquals(messageType, file.findMessageTypeByName("TestAllTypes"));
      assertNull(file.findMessageTypeByName("NoSuchType"));
      assertNull(file.findMessageTypeByName("protobuf_unittest.TestAllTypes"));
      for (int i = 0; i < file.getMessageTypes().size(); i++) {
        assertEquals(i, file.getMessageTypes().get(i).getIndex());
      }
  
      EnumDescriptor enumType = ForeignEnum.getDescriptor();
      assertEquals(enumType, file.getEnumTypes().get(0));
      assertEquals(enumType, file.findEnumTypeByName("ForeignEnum"));
      assertNull(file.findEnumTypeByName("NoSuchType"));
      assertNull(file.findEnumTypeByName("protobuf_unittest.ForeignEnum"));
      assertEquals(Arrays.asList(ImportEnum.getDescriptor()),
                   UnittestImport.getDescriptor().getEnumTypes());
      for (int i = 0; i < file.getEnumTypes().size(); i++) {
        assertEquals(i, file.getEnumTypes().get(i).getIndex());
      }
  
      ServiceDescriptor service = TestService.getDescriptor();
      assertEquals(service, file.getServices().get(0));
      assertEquals(service, file.findServiceByName("TestService"));
      assertNull(file.findServiceByName("NoSuchType"));
      assertNull(file.findServiceByName("protobuf_unittest.TestService"));
      assertEquals(Collections.emptyList(),
                   UnittestImport.getDescriptor().getServices());
      for (int i = 0; i < file.getServices().size(); i++) {
        assertEquals(i, file.getServices().get(i).getIndex());
      }
  
      FieldDescriptor extension =
        UnittestProto.optionalInt32Extension.getDescriptor();
      assertEquals(extension, file.getExtensions().get(0));
      assertEquals(extension,
                   file.findExtensionByName("optional_int32_extension"));
      assertNull(file.findExtensionByName("no_such_ext"));
      assertNull(file.findExtensionByName(
        "protobuf_unittest.optional_int32_extension"));
      assertEquals(Collections.emptyList(),
                   UnittestImport.getDescriptor().getExtensions());
      for (int i = 0; i < file.getExtensions().size(); i++) {
        assertEquals(i, file.getExtensions().get(i).getIndex());
      }
    }
  
    public void testDescriptor() throws Exception {
      Descriptor messageType = TestAllTypes.getDescriptor();
      Descriptor nestedType = TestAllTypes.NestedMessage.getDescriptor();
  
      assertEquals("TestAllTypes", messageType.getName());
      assertEquals("protobuf_unittest.TestAllTypes", messageType.getFullName());
      assertEquals(UnittestProto.getDescriptor(), messageType.getFile());
      assertNull(messageType.getContainingType());
      assertEquals(DescriptorProtos.MessageOptions.getDefaultInstance(),
                   messageType.getOptions());
      assertEquals("TestAllTypes", messageType.toProto().getName());
  
      assertEquals("NestedMessage", nestedType.getName());
      assertEquals("protobuf_unittest.TestAllTypes.NestedMessage",
                   nestedType.getFullName());
      assertEquals(UnittestProto.getDescriptor(), nestedType.getFile());
      assertEquals(messageType, nestedType.getContainingType());
  
      FieldDescriptor field = messageType.getFields().get(0);
      assertEquals("optional_int32", field.getName());
      assertEquals(field, messageType.findFieldByName("optional_int32"));
      assertNull(messageType.findFieldByName("no_such_field"));
      assertEquals(field, messageType.findFieldByNumber(1));
      assertNull(messageType.findFieldByNumber(571283));
      for (int i = 0; i < messageType.getFields().size(); i++) {
        assertEquals(i, messageType.getFields().get(i).getIndex());
      }
  
      assertEquals(nestedType, messageType.getNestedTypes().get(0));
      assertEquals(nestedType, messageType.findNestedTypeByName("NestedMessage"));
      assertNull(messageType.findNestedTypeByName("NoSuchType"));
      for (int i = 0; i < messageType.getNestedTypes().size(); i++) {
        assertEquals(i, messageType.getNestedTypes().get(i).getIndex());
      }
  
      EnumDescriptor enumType = TestAllTypes.NestedEnum.getDescriptor();
      assertEquals(enumType, messageType.getEnumTypes().get(0));
      assertEquals(enumType, messageType.findEnumTypeByName("NestedEnum"));
      assertNull(messageType.findEnumTypeByName("NoSuchType"));
      for (int i = 0; i < messageType.getEnumTypes().size(); i++) {
        assertEquals(i, messageType.getEnumTypes().get(i).getIndex());
      }
    }
  
    public void testFieldDescriptor() throws Exception {
      Descriptor messageType = TestAllTypes.getDescriptor();
      FieldDescriptor primitiveField =
        messageType.findFieldByName("optional_int32");
      FieldDescriptor enumField =
        messageType.findFieldByName("optional_nested_enum");
      FieldDescriptor messageField =
        messageType.findFieldByName("optional_foreign_message");
      FieldDescriptor cordField =
        messageType.findFieldByName("optional_cord");
      FieldDescriptor extension =
        UnittestProto.optionalInt32Extension.getDescriptor();
      FieldDescriptor nestedExtension = TestRequired.single.getDescriptor();
  
      assertEquals("optional_int32", primitiveField.getName());
      assertEquals("protobuf_unittest.TestAllTypes.optional_int32",
                   primitiveField.getFullName());
      assertEquals(1, primitiveField.getNumber());
      assertEquals(messageType, primitiveField.getContainingType());
      assertEquals(UnittestProto.getDescriptor(), primitiveField.getFile());
      assertEquals(FieldDescriptor.Type.INT32, primitiveField.getType());
      assertEquals(FieldDescriptor.JavaType.INT, primitiveField.getJavaType());
      assertEquals(DescriptorProtos.FieldOptions.getDefaultInstance(),
                   primitiveField.getOptions());
      assertFalse(primitiveField.isExtension());
      assertEquals("optional_int32", primitiveField.toProto().getName());
  
      assertEquals("optional_nested_enum", enumField.getName());
      assertEquals(FieldDescriptor.Type.ENUM, enumField.getType());
      assertEquals(FieldDescriptor.JavaType.ENUM, enumField.getJavaType());
      assertEquals(TestAllTypes.NestedEnum.getDescriptor(),
                   enumField.getEnumType());
  
      assertEquals("optional_foreign_message", messageField.getName());
      assertEquals(FieldDescriptor.Type.MESSAGE, messageField.getType());
      assertEquals(FieldDescriptor.JavaType.MESSAGE, messageField.getJavaType());
      assertEquals(ForeignMessage.getDescriptor(), messageField.getMessageType());
  
      assertEquals("optional_cord", cordField.getName());
      assertEquals(FieldDescriptor.Type.STRING, cordField.getType());
      assertEquals(FieldDescriptor.JavaType.STRING, cordField.getJavaType());
      assertEquals(DescriptorProtos.FieldOptions.CType.CORD,
                   cordField.getOptions().getCtype());
  
      assertEquals("optional_int32_extension", extension.getName());
      assertEquals("protobuf_unittest.optional_int32_extension",
                   extension.getFullName());
      assertEquals(1, extension.getNumber());
      assertEquals(TestAllExtensions.getDescriptor(),
                   extension.getContainingType());
      assertEquals(UnittestProto.getDescriptor(), extension.getFile());
      assertEquals(FieldDescriptor.Type.INT32, extension.getType());
      assertEquals(FieldDescriptor.JavaType.INT, extension.getJavaType());
      assertEquals(DescriptorProtos.FieldOptions.getDefaultInstance(),
                   extension.getOptions());
      assertTrue(extension.isExtension());
      assertEquals(null, extension.getExtensionScope());
      assertEquals("optional_int32_extension", extension.toProto().getName());
  
      assertEquals("single", nestedExtension.getName());
      assertEquals("protobuf_unittest.TestRequired.single",
                   nestedExtension.getFullName());
      assertEquals(TestRequired.getDescriptor(),
                   nestedExtension.getExtensionScope());
    }
  
    public void testFieldDescriptorLabel() throws Exception {
      FieldDescriptor requiredField =
        TestRequired.getDescriptor().findFieldByName("a");
      FieldDescriptor optionalField =
        TestAllTypes.getDescriptor().findFieldByName("optional_int32");
      FieldDescriptor repeatedField =
        TestAllTypes.getDescriptor().findFieldByName("repeated_int32");
  
      assertTrue(requiredField.isRequired());
      assertFalse(requiredField.isRepeated());
      assertFalse(optionalField.isRequired());
      assertFalse(optionalField.isRepeated());
      assertFalse(repeatedField.isRequired());
      assertTrue(repeatedField.isRepeated());
    }
  
    public void testFieldDescriptorDefault() throws Exception {
      Descriptor d = TestAllTypes.getDescriptor();
      assertFalse(d.findFieldByName("optional_int32").hasDefaultValue());
      assertEquals(0, d.findFieldByName("optional_int32").getDefaultValue());
      assertTrue(d.findFieldByName("default_int32").hasDefaultValue());
      assertEquals(41, d.findFieldByName("default_int32").getDefaultValue());
  
      d = TestExtremeDefaultValues.getDescriptor();
      assertEquals(
        ByteString.copyFrom(
          "\0\001\007\b\f\n\r\t\013\\\'\"\u00fe".getBytes("ISO-8859-1")),
        d.findFieldByName("escaped_bytes").getDefaultValue());
      assertEquals(-1, d.findFieldByName("large_uint32").getDefaultValue());
      assertEquals(-1L, d.findFieldByName("large_uint64").getDefaultValue());
    }
  
    public void testEnumDescriptor() throws Exception {
      EnumDescriptor enumType = ForeignEnum.getDescriptor();
      EnumDescriptor nestedType = TestAllTypes.NestedEnum.getDescriptor();
  
      assertEquals("ForeignEnum", enumType.getName());
      assertEquals("protobuf_unittest.ForeignEnum", enumType.getFullName());
      assertEquals(UnittestProto.getDescriptor(), enumType.getFile());
      assertNull(enumType.getContainingType());
      assertEquals(DescriptorProtos.EnumOptions.getDefaultInstance(),
                   enumType.getOptions());
  
      assertEquals("NestedEnum", nestedType.getName());
      assertEquals("protobuf_unittest.TestAllTypes.NestedEnum",
                   nestedType.getFullName());
      assertEquals(UnittestProto.getDescriptor(), nestedType.getFile());
      assertEquals(TestAllTypes.getDescriptor(), nestedType.getContainingType());
  
      EnumValueDescriptor value = ForeignEnum.FOREIGN_FOO.getValueDescriptor();
      assertEquals(value, enumType.getValues().get(0));
      assertEquals("FOREIGN_FOO", value.getName());
      assertEquals(4, value.getNumber());
      assertEquals(value, enumType.findValueByName("FOREIGN_FOO"));
      assertEquals(value, enumType.findValueByNumber(4));
      assertNull(enumType.findValueByName("NO_SUCH_VALUE"));
      for (int i = 0; i < enumType.getValues().size(); i++) {
        assertEquals(i, enumType.getValues().get(i).getIndex());
      }
    }
  
    public void testServiceDescriptor() throws Exception {
      ServiceDescriptor service = TestService.getDescriptor();
  
      assertEquals("TestService", service.getName());
      assertEquals("protobuf_unittest.TestService", service.getFullName());
      assertEquals(UnittestProto.getDescriptor(), service.getFile());
  
      assertEquals(2, service.getMethods().size());
  
      MethodDescriptor fooMethod = service.getMethods().get(0);
      assertEquals("Foo", fooMethod.getName());
      assertEquals(UnittestProto.FooRequest.getDescriptor(),
                   fooMethod.getInputType());
      assertEquals(UnittestProto.FooResponse.getDescriptor(),
                   fooMethod.getOutputType());
      assertEquals(fooMethod, service.findMethodByName("Foo"));
  
      MethodDescriptor barMethod = service.getMethods().get(1);
      assertEquals("Bar", barMethod.getName());
      assertEquals(UnittestProto.BarRequest.getDescriptor(),
                   barMethod.getInputType());
      assertEquals(UnittestProto.BarResponse.getDescriptor(),
                   barMethod.getOutputType());
      assertEquals(barMethod, service.findMethodByName("Bar"));
  
      assertNull(service.findMethodByName("NoSuchMethod"));
  
      for (int i = 0; i < service.getMethods().size(); i++) {
        assertEquals(i, service.getMethods().get(i).getIndex());
      }
    }
  
  
    public void testCustomOptions() throws Exception {
      Descriptor descriptor =
        UnittestCustomOptions.TestMessageWithCustomOptions.getDescriptor();
  
      assertTrue(
        descriptor.getOptions().hasExtension(UnittestCustomOptions.messageOpt1));
      assertEquals(Integer.valueOf(-56),
        descriptor.getOptions().getExtension(UnittestCustomOptions.messageOpt1));
  
      FieldDescriptor field = descriptor.findFieldByName("field1");
      assertNotNull(field);
  
      assertTrue(
        field.getOptions().hasExtension(UnittestCustomOptions.fieldOpt1));
      assertEquals(Long.valueOf(8765432109L),
        field.getOptions().getExtension(UnittestCustomOptions.fieldOpt1));
  
      EnumDescriptor enumType =
        UnittestCustomOptions.TestMessageWithCustomOptions.AnEnum.getDescriptor();
  
      assertTrue(
        enumType.getOptions().hasExtension(UnittestCustomOptions.enumOpt1));
      assertEquals(Integer.valueOf(-789),
        enumType.getOptions().getExtension(UnittestCustomOptions.enumOpt1));
  
      ServiceDescriptor service =
        UnittestCustomOptions.TestServiceWithCustomOptions.getDescriptor();
  
      assertTrue(
        service.getOptions().hasExtension(UnittestCustomOptions.serviceOpt1));
      assertEquals(Long.valueOf(-9876543210L),
        service.getOptions().getExtension(UnittestCustomOptions.serviceOpt1));
  
      MethodDescriptor method = service.findMethodByName("Foo");
      assertNotNull(method);
  
      assertTrue(
        method.getOptions().hasExtension(UnittestCustomOptions.methodOpt1));
      assertEquals(UnittestCustomOptions.MethodOpt1.METHODOPT1_VAL2,
        method.getOptions().getExtension(UnittestCustomOptions.methodOpt1));
    }
  
    /**
     * Test that the FieldDescriptor.Type enum is the same as the
     * WireFormat.FieldType enum.
     */
    public void testFieldTypeTablesMatch() throws Exception {
      FieldDescriptor.Type[] values1 = FieldDescriptor.Type.values();
      WireFormat.FieldType[] values2 = WireFormat.FieldType.values();
  
      assertEquals(values1.length, values2.length);
  
      for (int i = 0; i < values1.length; i++) {
        assertEquals(values1[i].toString(), values2[i].toString());
      }
    }
  
    /**
     * Test that the FieldDescriptor.JavaType enum is the same as the
     * WireFormat.JavaType enum.
     */
    public void testJavaTypeTablesMatch() throws Exception {
      FieldDescriptor.JavaType[] values1 = FieldDescriptor.JavaType.values();
      WireFormat.JavaType[] values2 = WireFormat.JavaType.values();
  
      assertEquals(values1.length, values2.length);
  
      for (int i = 0; i < values1.length; i++) {
        assertEquals(values1[i].toString(), values2[i].toString());
      }
    }
  
    public void testEnormousDescriptor() throws Exception {
      // The descriptor for this file is larger than 64k, yet it did not cause
      // a compiler error due to an over-long string literal.
      assertTrue(
          UnittestEnormousDescriptor.getDescriptor()
            .toProto().getSerializedSize() > 65536);
    }
  
    /**
     * Tests that the DescriptorValidationException works as intended.
     */
    public void testDescriptorValidatorException() throws Exception {
      FileDescriptorProto fileDescriptorProto = FileDescriptorProto.newBuilder()
        .setName("foo.proto")
        .addMessageType(DescriptorProto.newBuilder()
        .setName("Foo")
          .addField(FieldDescriptorProto.newBuilder()
            .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
            .setType(FieldDescriptorProto.Type.TYPE_INT32)
            .setName("foo")
            .setNumber(1)
            .setDefaultValue("invalid")
            .build())
          .build())
        .build();
      try {
        Descriptors.FileDescriptor.buildFrom(fileDescriptorProto,
            new FileDescriptor[0]);
        fail("DescriptorValidationException expected");
      } catch (DescriptorValidationException e) {
        // Expected; check that the error message contains some useful hints
        assertTrue(e.getMessage().indexOf("foo") != -1);
        assertTrue(e.getMessage().indexOf("Foo") != -1);
        assertTrue(e.getMessage().indexOf("invalid") != -1);
        assertTrue(e.getCause() instanceof NumberFormatException);
        assertTrue(e.getCause().getMessage().indexOf("invalid") != -1);
      }
    }
  
    /**
     * Tests the translate/crosslink for an example where a message field's name
     * and type name are the same.
     */
    public void testDescriptorComplexCrosslink() throws Exception {
      FileDescriptorProto fileDescriptorProto = FileDescriptorProto.newBuilder()
        .setName("foo.proto")
        .addMessageType(DescriptorProto.newBuilder()
          .setName("Foo")
          .addField(FieldDescriptorProto.newBuilder()
            .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
            .setType(FieldDescriptorProto.Type.TYPE_INT32)
            .setName("foo")
            .setNumber(1)
            .build())
          .build())
        .addMessageType(DescriptorProto.newBuilder()
          .setName("Bar")
          .addField(FieldDescriptorProto.newBuilder()
            .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
            .setTypeName("Foo")
            .setName("Foo")
            .setNumber(1)
            .build())
          .build())
        .build();
      // translate and crosslink
      FileDescriptor file =
        Descriptors.FileDescriptor.buildFrom(fileDescriptorProto, 
            new FileDescriptor[0]);
      // verify resulting descriptors
      assertNotNull(file);
      List<Descriptor> msglist = file.getMessageTypes();
      assertNotNull(msglist);
      assertTrue(msglist.size() == 2);
      boolean barFound = false;
      for (Descriptor desc : msglist) {
        if (desc.getName().equals("Bar")) {
          barFound = true;
          assertNotNull(desc.getFields());
          List<FieldDescriptor> fieldlist = desc.getFields();
          assertNotNull(fieldlist);
          assertTrue(fieldlist.size() == 1);
          assertTrue(fieldlist.get(0).getType() == FieldDescriptor.Type.MESSAGE);
          assertTrue(fieldlist.get(0).getMessageType().getName().equals("Foo"));
        }
      }
      assertTrue(barFound);
    }
    
    public void testInvalidPublicDependency() throws Exception {
      FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
          .setName("foo.proto") .build();
      FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
          .setName("boo.proto")
          .addDependency("foo.proto")
          .addPublicDependency(1)  // Error, should be 0.
          .build();
      FileDescriptor fooFile = Descriptors.FileDescriptor.buildFrom(fooProto,
          new FileDescriptor[0]);
      try {
        Descriptors.FileDescriptor.buildFrom(barProto,
            new FileDescriptor[] {fooFile});
        fail("DescriptorValidationException expected");
      } catch (DescriptorValidationException e) {
        assertTrue(
            e.getMessage().indexOf("Invalid public dependency index.") != -1);
      }
    }
  
    public void testHiddenDependency() throws Exception {
      FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
          .setName("bar.proto")
          .addMessageType(DescriptorProto.newBuilder().setName("Bar"))
          .build();
      FileDescriptorProto forwardProto = FileDescriptorProto.newBuilder()
          .setName("forward.proto")
          .addDependency("bar.proto")
          .build();
      FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
          .setName("foo.proto")
          .addDependency("forward.proto")
          .addMessageType(DescriptorProto.newBuilder()
              .setName("Foo")
              .addField(FieldDescriptorProto.newBuilder()
                  .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
                  .setTypeName("Bar")
                  .setName("bar")
                  .setNumber(1)))
          .build();
      FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
          barProto, new FileDescriptor[0]);
      FileDescriptor forwardFile = Descriptors.FileDescriptor.buildFrom(
          forwardProto, new FileDescriptor[] {barFile});
  
      try {
        Descriptors.FileDescriptor.buildFrom(
            fooProto, new FileDescriptor[] {forwardFile});
        fail("DescriptorValidationException expected");
      } catch (DescriptorValidationException e) {
        assertTrue(e.getMessage().indexOf("Bar") != -1);
        assertTrue(e.getMessage().indexOf("is not defined") != -1);
      }
    }
  
    public void testPublicDependency() throws Exception {
      FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
          .setName("bar.proto")
          .addMessageType(DescriptorProto.newBuilder().setName("Bar"))
          .build();
      FileDescriptorProto forwardProto = FileDescriptorProto.newBuilder()
          .setName("forward.proto")
          .addDependency("bar.proto")
          .addPublicDependency(0)
          .build();
      FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
          .setName("foo.proto")
          .addDependency("forward.proto")
          .addMessageType(DescriptorProto.newBuilder()
              .setName("Foo")
              .addField(FieldDescriptorProto.newBuilder()
                  .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
                  .setTypeName("Bar")
                  .setName("bar")
                  .setNumber(1)))
          .build();
      FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
          barProto, new FileDescriptor[0]);
      FileDescriptor forwardFile = Descriptors.FileDescriptor.buildFrom(
          forwardProto, new FileDescriptor[]{barFile});
      Descriptors.FileDescriptor.buildFrom(
          fooProto, new FileDescriptor[] {forwardFile});
    }
    
    /**
     * Tests the translate/crosslink for an example with a more complex namespace
     * referencing.
     */
    public void testComplexNamespacePublicDependency() throws Exception {
      FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
          .setName("bar.proto")
          .setPackage("a.b.c.d.bar.shared")
          .addEnumType(EnumDescriptorProto.newBuilder()
              .setName("MyEnum")
              .addValue(EnumValueDescriptorProto.newBuilder()
                  .setName("BLAH")
                  .setNumber(1)))
          .build();
      FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
          .setName("foo.proto")
          .addDependency("bar.proto")
          .setPackage("a.b.c.d.foo.shared")
          .addMessageType(DescriptorProto.newBuilder()
              .setName("MyMessage")
              .addField(FieldDescriptorProto.newBuilder()
                  .setLabel(FieldDescriptorProto.Label.LABEL_REPEATED)
                  .setTypeName("bar.shared.MyEnum")
                  .setName("MyField")
                  .setNumber(1)))
          .build();
      // translate and crosslink
      FileDescriptor fooFile = Descriptors.FileDescriptor.buildFrom(
          fooProto, new FileDescriptor[0]);
      FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
          barProto, new FileDescriptor[]{fooFile});
      // verify resulting descriptors
      assertNotNull(barFile);
      List<Descriptor> msglist = barFile.getMessageTypes();
      assertNotNull(msglist);
      assertTrue(msglist.size() == 1);
      Descriptor desc = msglist.get(0);
      if (desc.getName().equals("MyMessage")) {
        assertNotNull(desc.getFields());
        List<FieldDescriptor> fieldlist = desc.getFields();
        assertNotNull(fieldlist);
        assertTrue(fieldlist.size() == 1);
        FieldDescriptor field = fieldlist.get(0);
        assertTrue(field.getType() == FieldDescriptor.Type.ENUM);
        assertTrue(field.getEnumType().getName().equals("MyEnum"));
        assertTrue(field.getEnumType().getFile().getName().equals("bar.proto"));
        assertTrue(field.getEnumType().getFile().getPackage().equals(
            "a.b.c.d.bar.shared"));
      }   
    }
  }
  